E 688 94 (2011)

Designation E688 − 94 (Reapproved 2011) Standard Test Methods for Waste Glass as a Raw Material for Glass Manufacturing1 This standard is issued under the fixed designation E688; the number immediatel[.]

Designation: E688 − 94 (Reapproved 2011) Standard Test Methods for Waste Glass as a Raw Material for Glass Manufacturing1 This standard is issued under the fixed designation E688; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision A number in parentheses indicates the year of last reapproval A superscript epsilon (´) indicates an editorial change since the last revision or reapproval by Atomic Absorption Spectrophotometry (Withdrawn 1979)3 D4129 Test Method for Total and Organic Carbon in Water by High Temperature Oxidation and by Coulometric Detection E11 Specification for Woven Wire Test Sieve Cloth and Test Sieves E105 Practice for Probability Sampling of Materials E122 Practice for Calculating Sample Size to Estimate, With Specified Precision, the Average for a Characteristic of a Lot or Process Scope 1.1 These test methods give the various tests for assessing the compliance of glass recovered from wastes for use as a raw material for glass manufacturing 1.2 The test methods combine visual examinations with both chemical and physical tests A flow chart of the testing sequence is included in this test method (see Fig 1) 1.3 The values stated in SI units are to be regarded as standard No other units of measurement are included in this standard 1.3.1 Exception—The values given in parentheses are for information only 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use For hazard statements, see 5.3, 5.5, Section 6, 11.1.1 and 12.3.2 Significance and Use 3.1 These test methods provide a means for determining whether waste glass is suitable for use as a raw material for glass manufacturing Apparatus 4.1 The following various items of equipment required may be purchased from most laboratory supply houses: 4.1.1 Aspirator 4.1.2 Balance 4.1.3 Burner, Fisher (Meker) type 4.1.4 Crucible, porcelain or other ceramic 4.1.5 Crucible, platinum 4.1.6 Flask, filtering, with side tube, 2000-ml 4.1.7 Funnel, Büchner, approximately 171 mm in diameter 4.1.8 Funnel, approximately 150 mm in diameter, filtering 4.1.9 Furnace, 540°C or 1000°F 4.1.10 Clamps, tubing, screw compressor 4.1.11 Magnet, C-shaped, Alnico 4.1.12 Magnifier, 5×, 10× 4.1.13 Oven, 110°C or 230°F 4.1.14 Scales, triple-beam 4.1.15 Sieves, U.S Standard Series—50 mm (2 in.), 6.3 mm (1⁄4 in.), 1.18 mm (No 16), 850 µm (No 20), 425 µm (No 40), 250 µm (No 60), 106 µm (No 140), conforming to Specification E11 4.1.16 Sink-Float Standard, sp gr 2.65 4.1.17 Triangle, platinum Referenced Documents 2.1 ASTM Standards:2 C169 Test Methods for Chemical Analysis of Soda-Lime and Borosilicate Glass C566 Test Method for Total Evaporable Moisture Content of Aggregate by Drying C702 Practice for Reducing Samples of Aggregate to Testing Size C729 Test Method for Density of Glass by the Sink-Float Comparator D1068 Test Methods for Iron in Water D1193 Specification for Reagent Water D2576 Method of Test for Metals in Water and Waste Water These test methods are under the jurisdiction of ASTM Committee D34 on Waste Management and are the direct responsibility of Subcommittee D34.03 on Treatment, Recovery and Reuse Current edition approved July 1, 2011 Published December 2011 Originally approved in 1979 Last previous edition approved in 2006 as E688 – 94 (2006) DOI: 10.1520/E0688-94R11 For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org For Annual Book of ASTM Standards volume information, refer to the standard’s Document Summary page on the ASTM website The last approved version of this historical standard is referenced on www.astm.org Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959 United States E688 − 94 (2011) FIG Simplified Testing Flow Chart 4.1.18 Tubing, vinyl.4 4.1.19 Other ancillary laboratory equipment 5.2 Purity of Water— Unless otherwise indicated, references to water shall be understood to mean reagent water, Type II, as defined in Specification D1193 Reagents and Materials 5.3 Warning—Acetone (see 15.5)—This substance is highly flammable (Class B) and must not be used in the vicinity of open flames or other ignition sources Vapors should not be inhaled, since they can cause skin and membrane irritation 5.1 Purity of Reagents—Reagent grade chemicals shall be used in all tests Unless otherwise indicated, it is intended that all reagents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society, where such specifications are available.5 Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high purity to permit its use without lessening the accuracy of the determination 5.4 Ethyl Alcohol, denatured 5.5 Hydrochloric Acid (3 N and N) (see 12.3.2/15.11)—Prepare N acid by diluting part of concentrated hydrochloric acid (HCl, sp gr 1.19) with parts of water Prepare N acid by diluting part of concentrated HCl with part of water (Warning —These materials are corrosive and injurious to the skin as well as irritating to the eyes and mucous membranes.) Tygon plastic tubing, available from Norton Co., Plastics and Synthetics Div., Dept TR2, 12 East Ave., Tallmadge, OH 44278, or equivalent, has been found suitable for this purpose Reagent Chemicals, American Chemical Society Specifications, American Chemical Society, Washington, DC For suggestions on the testing of reagents not listed by the American Chemical Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and National Formulary, U.S Pharmacopeial Convention, Inc (USPC), Rockville, MD 5.6 Potassium Hydroxide, Saturated Solution—Add 100 g of potassium hydroxide (KOH) slowly, while stirring, to 100 ml water Store this solution in a polyethylene bottle This solution is corrosive and injurious to the skin E688 − 94 (2011) funnel is full When the hand over the opening is removed, glass meeting the requirements will flow out of the funnel One or two light taps on the funnel may be used to begin or aid flow If the glass fails to flow out of the specified funnel and both producers and users agree, a second funnel test (Method B) may be performed; this test will measure the flow properties of a somewhat more sticky glass 5.7 Sodium Carbonate (Na2CO3) 5.8 sym-Tetrabromoethane (Acetylene Tetrabromide) (sp gr 2.964)—This substance has a threshold limit value (8 h time-weighted average exposure) of ppm and a short time exposure limit (15 min) of 1.25 ppm It must be used in a hood or under conditions of ensured ventilation Hazards 8.4 Method B—Use the same procedure as in Method A except that the dimensions of the second funnel shall be: stem internal diameter, 38 mm; stem length, 48 mm; top diameter, 170 mm 6.1 The analyst should be aware of good laboratory practices Adequate ventilation is necessary, particularly for handling sym-tetrabromoethane and the density liquids used in 15.7.1 – 15.10.1 The flammability of acetone must be considered when it is used in 15.5 Moisture Content 9.1 Procedure—Dry five 454-g (1-lb) test samples (see 7.2) to constant weight in accordance with Test Method C566 Drying time may be in the order of h at 110°C (230°F) Record the dry weight of at least one sample for use in 9.2 Use the remaining dry samples for testing according to Sections 10 – 14 6.2 Due to the origins of glass samples in municipal wastes destined for disposal, common sense dictates that some precautions should be observed when conducting tests on the samples Recommended hygienic practices include using gloves when handling waste glass and washing hands before eating or smoking 9.2 Calculation— Calculate the moisture content as follows: Sampling Moisture, % 7.1 Gross Sample—Take a grab sample weighing 36 kg (80 lb) in such a manner that it will be representative of the lot as described in Practices E105 and E122 ~ original weight dry weight! 100 original weight (1) 10 Particle Size 10.1 Procedure—Screen a sample from 9.1 on a 50-mm (2-in.) sieve Weigh the material remaining on the sieve Screen the material passing the sieve on a 106-µm (No 140) sieve An intervening sieve, such as a 212 µm (No 70) may be used merely to reduce the amount presented to the test sieve Weigh material passing through the 106-µm sieve Shake all sieves mechanically for 10 or by hand to achieve equivalent results Other intervening screen sizes may be utilized 7.2 Test Sample Preparation—Reduce the gross sample to two samples, each weighing 18 kg (40 lb) by a method as described in Practice C702 Use one sample for testing for inorganic material Reduce the other sample by coning and quartering to produce at least seven samples, each weighing 454 g (1 lb), to be used for the remaining tests described in Sections – 14 7.3 Sample Preservation—Store the gross sample and subsequent samples in such a manner as to prevent not only the loss of contaminants but to prevent further contamination, until the necessary tests can be performed It is recommended that samples be stored in sealed plastic bags (75 µm or mil) or other airtight containers in order to avoid gain or loss of moisture 10.2 Calculations—Calculate the percent of plus 50-mm and minus 106-µm material as follows: Plus 50 mm material, % ~ A/W ! 100 (2) Minus 106 µm material, % ~ B/W ! 100 (3) where: A = weight of material on 50-mm sieve, B = weight of material through 106-µm sieve, and W = dry weight of sample Flow Test6 8.1 This test is used to ensure that the sample of glass shows no drainage, is noncaking, and free flowing 11 Total Organics (Paper, Plastic, and Other Combustibles) 8.2 If the sample is 90 % larger than will pass through a 1.18-mm (No 16) sieve, the requirements will be met if the sample shows no drainage of water 11.1 Indirect Method: 11.1.1 Procedure—Using a sample from 9.1, place the sample in an uncovered ceramic crucible(s) and heat to 540°C (1000°F) Maintain this temperature for 1⁄2 h or until all flame and smoke have ceased (Warning—Overheating can cause the glass particles to fuse together Allow the sample to cool to room temperature, weigh, and calculate the percent total organics Reserve the sample or use an alternative dry sample for subsequent tests.) 11.1.2 Calculation—Calculate the percent total organics as follows: 8.3 Method A—If the sample contains in excess of 10 % through a 1.18-mm (No 16) sieve, screen a sample through the 1.18-mm sieve, 454 g (1 lb) of this material must flow out of the funnel as follows: Fit a powder funnel having a uniform internal stem diameter of 18 mm, a stem length of 30 mm, and a top of 80 mm, in a rack, and close off the bottom by the palm of a hand Pour the sample to be tested into the funnel until the More detailed testing procedures and the effect of compaction are discussed by Carson, J W., in International Journal of Powder Metallurgy and Powder Technology, vol 11, 1975, pp 233–239 Total organics, % 100 weight after ignition 100 dry weight of sample (4) E688 − 94 (2011) 13 Off-Color Glass 13.1 This test is used to test for off-color glass in colorsorted glass used by the container industry Glass samples that are plus 1.18-mm (No 16 sieve) particle size can be tested by visual means Glass samples that are minus 1.18-mm particle size cannot be tested by visual means but must be chemically analyzed 13.2 Coarse Material—Plus 1.18-mm 13.2.1 Procedure—Spread the dry sample from 9.1 on a clean, dry surface that is illuminated to at least 2150 lx (200 fc) Visually pick out the off-color glass particles The off-color particles should be segregated into amber, green (emerald green and Georgia green should be segregated when examining a flint glass because emerald green has a chromium content ten times that of Georgia green), flint, and other glass fractions Georgia green can be visually distinguished from emerald green, since Georgia green is lighter in color Other glass colors are those other than the colors listed Save the fractions 13.2.2 Calculation— Calculate the percent off-color glass as follows: 11.2 Direct Method for Organic Carbon—Organic carbon can only be inferred from the method in 11.1 Organic carbon can be determined directly by the method in this section 11.2.1 Procedure—Organic carbon can be determined directly by an instrumental method such as coulometrics.7 Test Method D4129 uses this instrumentation for total and organic carbon in water The instrument can be readily adapted to solid materials such as waste glass 12 Magnetic Material (Iron Contamination) 12.1 The method of testing for iron contamination will depend on the particle size of the sample 12.2 Determination of Iron Contamination in Coarse Glass (Larger Than mm in Size): 12.2.1 Procedure—Using the sample from 9.1 or from a replicate dry sample, spread a portion of the sample over a clean, dry surface in such a manner as not to have any piles over three particles deep Cover the poles of a C-shaped Alnico magnet or its equivalent with a piece of paper or plastic film Draw the magnet slowly through the glass particles so as to collect any magnetic material present Transfer the magnetic material to an appropriate container by removing the cover from the magnet, while holding it over the container Continue this process until all of the sample has been exposed to the magnet Screen at 6.3 mm (1⁄4 in.); then combine the magnetic material from all portions of the sample, weigh, and calculate the percent magnetic material Reserve all portions of the sample, or from a replicate sample for subsequent tests 12.2.2 Calculation—Calculate the percent magnetic material as follows: Magnetic material, % weight of tramp iron 100 dry weight of sample Off color glass, % weight of iron ~ Fe 11 ! 100 dry weight of sample (7) 13.3 Examples—The following examples are used to demonstrate the method of calculating the off-color fraction: 13.3.1 Example 1: Given: A flint glass analytical sample with a dry weight of 447.8 g Off-Color Fractions: Amber 13.4 g Georgia green 21.9 g Emerald green 2.2 g Other 2.2 g (5) Then: 12.3 Determination of Iron Contamination in Fine Glass (Smaller than mm Size): 12.3.1 Weigh 100 g from the sample from 11.1 or from a replicate 12.3.2 Add 250 ml of N hydrochloric acid (HCl) and slowly heat to a vigorous boil Stir while boiling (Warning— Rapid heating may cause “bumping.”) 12.3.3 Cool the sample and filter through a medium filter paper Catch the filtrate in a 500-ml volumetric flask and wash the insolvable sample at least five times with warm distilled water Wash water should not exceed 500 ml Allow the flask and its contents to cool to room temperature and dilute to volume with distilled water 12.3.4 Transfer an appropriate sized aliquot to a 200-ml volumetric flask and analyze for iron, by either Test Methods D1068 or Test Method D2576 12.3.5 Calculation—Calculate the percent iron as follows: Iron, % weight of off color glass 100 dry weight of sample Amber, % 13.4 100 3.0 447.8 Georgia green, % 21.9 100 4.9 447.8 Emerald green, % 2.2 100 0.5 447.8 Equivalent emerald green, % 0.51 Other, % 4.9 1.0 10 2.2 100 0.5 447.8 Flint, % 100 ~ 3.011.010.5! 95.5 13.3.2 Example 2: Given: An amber glass analytical sample with a dry weight of 446 g Off-Color Fractions: A Emerald and Georgia green need not be segregated for amber glass determination Then: (6) To report results as % Fe2O3, multiply by 1.43 Model 5010 Coulometer, available from Coulometrics Inc., a subsidiary of UIC Inc., P.O Box 563, Joliet, IL 60434 Flint, % 19.9 100 4.5 446 Green, % 17.8 100 4.0 446 E688 − 94 (2011) Other, % coated with a painted or foil paper label or other coating Save these for subsequent test for the presence of free metals Reserve the remaining inorganic particles for 15.4 4.5 100 1.0 446 Amber, % 100 ~ 4.5 %14.011.0! 90.5 15.4 Weigh the inorganic particles from 15.3 If the sample weighs more than g, split the sample into aliquots so that not more than g will be fused at one time in a single crucible Weigh out seven times as much sodium carbonate (Na2CO3) as the weight of the sample(s) Mix the sample(s) with its charge of sodium carbonate and add to the crucible(s) Platinum crucibles are preferred but certain metals may destroy the crucible Porcelain crucibles with covers may be substituted Heat the mixture on a Meker-type laboratory burner and fuse the mixture for 10 at the maximum heat attainable 15.4.1 The purpose of the fusion is to eliminate particles that are obviously not refractory so as to facilitate the inspection of the remaining particles The particles remaining after fusion may not necessarily be refractory in glass furnaces so must be evaluated individually 13.4 Fine Material—Minus 1.18 mm 13.4.1 Procedure—Chemically analyze a representative sample of the glass in accordance with procedures found in Test Method C169 Test for: (1) Cr2O3; (2) Fe2O3; (3) FeO, and (4) any other coloring species of interest 13.4.2 Color is an indicator of the oxidation state of cullet The buyers and sellers of cullet may agree to limits on the concentration of coloring species because changes in oxidation state can affect heat transfer in the melt, cause the release of dissolved gases, and thus change furnace efficiency and glass quality Limits on coloring species may be expressed through the REDOX NUMBER as follows, where Redox number Fe 11 Fe 111 (8) 15.5 Place the cooled crucible in a 250-ml beaker Neutralize the fused material with N hydrochloric acid (HCl) Rinse the particles from the crucible Dilute the solution with water, decant and dispose of the spent liquid Wash the residue with water If the presence of a residue obscures the particles, add a few millilitres of concentrated potassium hydroxide (KOH) solution and warm to dissolve Again dilute the solution with water, decant, discard the spent liquid, and wash the residue with water Rinse the particles with acetone and allow to air dry %F eO 0.7779 ~ %Fe O 3 0.6994! ~ %FeO 0.7779! An increasing Redox number indicates a more reduced state of the material 14 Chemical Analysis 14.1 A chemical analysis may be necessary to establish the acceptability of a glass sample Chemical analysis of glass samples shall be done in accordance with procedures for routine analysis found in Test Methods C169 or to procedures mutually agreeable to the parties involved 15.6 Examine the particles remaining Particles that remain nondriable when probed with a needle and appear unaltered except for possible reduction in size will be reserved for routine examination by a petrographic microscope or subjected to a standard glass melt test, or both Questionable particles can be examined by other means (for example, X-ray diffraction, emission spectroscopy, or microchemistry) Record the number of particles 15.6.1 These materials are shown to be refractory in glass furnaces when they exist as particles of 250 µm or larger: corundum, mullite, zircon, chromite, spinel, sillimanite, andalusite, kyanite, and cassiterite 15 Inorganic Material (Nonmagnetic Metal, Refractories, and Other Solid Inorganics) 15.1 Sample Preparation—Using the 18-kg (40-lb) sample from 7.2, screen through a 6.3-mm (1⁄4-in.) sieve or screen If the sample is not dry, the material on the screen or sieve must be washed on the screen or sieve with a flowing stream of water to remove adhering particles Reserve the minus 6.3-mm material for 15.3 and dry if necessary 15.2 For Material Remaining on the Screen—Pick out non-glass particles and determine if any are of magnetic metal, nonmagnetic metal or other inorganic materials Count the number of such particles Discard any of the remaining particles and reserve the rest for calculating total inorganic materials From the remaining glass material, pick any pieces that appear to be coated with a painted or foil paper label or other coating Save these for subsequent test for the presence of free metals Discard the remaining plus 6.3-mm material 15.7 Weigh the minus 250-µm material from 15.3 If the sample weight exceeds 450 g, take a representative sample weighing 450 g; otherwise use the whole sample Separate the heavy inorganic particles from the glass using a dense liquid of 2.65 sp gr 15.7.1 A dense liquid of 2.65 sp gr may be prepared by slowly adding denatured ethyl alcohol while stirring to symtetrabromoethane until a 2.65 sp gr density standard is no longer buoyant Other liquids of 2.65 sp gr may be used 15.3 Screen the dry minus 6.3-mm material from 15.1 through a 850-µm (No 20) sieve Reserve the minus 850-µm material for 15.7 Spread the plus 850-µm material on a clean dry surface that is illuminated to 2150 lx (200 fc) and visually pick out the non-glass particles using 5× magnification Discard any particles attracted to a magnet and all organic material Weigh the remaining inorganic particles and reserve the weight for calculating total inorganic material Pick out and count the nonmagnetic metal particles In addition, from the remaining glass material, pick any pieces that appear to be 15.8 Construct a separatory apparatus by slipping a 100-mm piece of vinyl tubing about 15 mm in diameter on the stem of a large filtering funnel Install two screw compression-type tubing clamps on the tubing about 50 mm apart Tighten the lower clamp to completely close off the tubing and adjust the upper clamp merely tight enough to remain in place Add enough dense liquid to fill the separatory apparatus about half full E688 − 94 (2011) 15.12.2 Calculate the percent weight of inorganic materials, between 6.3 mm and 850 µm (1⁄4 in and No 20) Wi(+850 µm), as follows: 15.9 Add the sample from 15.7 and enough dense liquid to nearly fill the separatory apparatus Stir the sample periodically, and allow sufficient intervals between the stirring to permit the materials to separate Should the accumulation of heavy particles in the tubing tend to fill up the upper clamp, close off the upper clamp, place a 100-ml beaker under the tubing, open the lower clamp, and flush the particles into the beaker Close off the lower clamp and open the upper clamp as before Continue stirring for a total of ten times It may be necessary to repeat the removal of particles between stirrings and after the final stirring Allow the particles to settle in the beaker, and decant the excess heavy liquid back into the separatory apparatus W i ~ 1850 µm ! (10) where W2 is the weight of 6.3 mm − 850 µm inorganic material reserved from 15.3 15.12.3 Calculate the percent weight of inorganic materials, smaller than 850 µm (No 20), Wi (−850 µm), as follows: W i ~ 2850 µm ! 100 W 18 (11) where W3 is the weight of − 850 µm inorganic material reserved from 15.10 15.12.4 Calculate the percent weight of total inorganic materials, Wt, as follows: 15.10 After the final decantation into the separatory apparatus, dilute the remaining heavy liquid in the beaker with acetone, allow the particles to settle, and decant the dilute heavy liquid into the evaporating dish (See 15.10.1) Wash the heavy particles with acetone, decant, and discard the liquid Allow the heavy particles to dry and weigh Reserve this material for calculating total inorganic materials If the heavy particles exceed g, screen through a 250-µm sieve and reserve the plus 250-µm heavy particles for 15.11 Discard the minus 250-µm particles 15.10.1 The heavy liquid containing glass and other light particles may be conserved by filtering the liquid through a Büchner funnel, using a rapid filter paper and vacuum Transfer the filtered liquid to a storage reservoir, which should be covered to retard evaporation of alcohol Rinse the particles remaining on the filter with acetone to remove additional heavy liquid Transfer the dilute heavy liquid to the evaporating reservoir, and allow the acetone to evaporate Periodically test the density of the dilute liquid with a 2.65 sp gr sink-float density standard (see Test Method C729) When the liquid exceeds the 2.65 sp gr, filter and transfer to the storage reservoir for reuse Discard the glass and other light particles W t W i ~ 16.3 mm! 1W i ~ 1850 µm ! 1W i ~ 2850 µm ! (12) 15.13 Test for Presence of Free-Metals—After following the calculation procedures in 15.12, gather the inorganic material particles from 15.2, 15.3, 15.6, and 15.10 along with the pieces of coated glass from 15.3 and 15.4 15.13.1 Procedure—Place the inorganic particles in a 15-mL or other appropriate sized test tube Add a sufficient amount of a % alcoholic solution of o-dinitrobenzene to half cover the particles in each test tube Add 0.5 N NaOH to each test tube until the particles are covered (this will constitute a 1:1 mixture) Suspend the test tubes in boiling water The development of a violet color indicates the presence of aluminum, zinc, lead, or tin metal, or a combination thereof NOTE 1—This test is effective even if these metals have an oxide surface coating 15.14 Chemical Analysis—This procedure does not separate or identify any inorganic materials other than glass smaller than 850 µm in size and having a specific gravity less than 2.65 If such material is suspected to be present, the methods cited in Section 14 should be used 15.11 Test the heavy particle sample from 15.10 in the same manner as found in 15.4 and 15.5 by fusion with sodium carbonate and dissolution of the fusion with N HCl If a platinum crucible is used, be sure all metals have been removed After drying, screen the particles through the 425-µm and 250-µm sieves Particles that remain nonfriable when probed with a needle and appear unaltered except for possible reduction in size will be considered potential refractories Record the number of potential refractory particles found on each sieve As in 15.6 these particles may be examined further 16 Precision and Bias 16.1 The precision and bias of these methods have not yet been established 17 Flow Chart 17.1 The accompanying flow chart (see Fig 1) is included to clarify the complex sequence of tests to be carried out in accordance with Sections – 15 15.12 Calculations: 15.12.1 Calculate the percent weight of inorganic materials larger than 6.3 mm (1⁄4 in.), Wi (+ 6.3 mm), as follows: 100 W W i ~ 16.3 mm! 18 100 W 18 18 Keywords 18.1 chemical tests; glass; glass cullet; glass manufacturing; glass recovery; inorganic contaminants; metallic contaminants; off-color glass; organic contaminants; physical tests; refractory contaminants; test methods; waste glass (9) where W is the weight of +6.3 mm inorganic material reserved from 15.2 E688 − 94 (2011) ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned in this standard Users of this standard are expressly advised that determination of the validity of any such patent rights, and the risk of infringement of such rights, are entirely their own responsibility This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and if not revised, either reapproved or withdrawn Your comments are invited either for revision of this standard or for additional standards and should be addressed to ASTM International Headquarters Your comments will receive careful consideration at a meeting of the responsible technical committee, which you may attend If you feel that your comments have not received a fair hearing you should make your views known to the ASTM Committee on Standards, at the address shown below This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the above address or at 610-832-9585 (phone), 610-832-9555 (fax), or service@astm.org (e-mail); or through the ASTM website (www.astm.org) Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/ COPYRIGHT/)